Buttonhole mechanisms for zigzag sewing machines



J. SZOSTAK BUTTONHOLE MECHANISMS FOR ZIGZAG SEWING MACHINES Filed July 17, 1964 6 Sheets-Sheet 2 J. SZOSTAK Feb. 28, 1967 BUTTONHOLE MECHANISMS FOR ZIGZAG SEWING MACHINES Filed July 17. 1964 6 Sheets-Sheet I5 IN V EN TOR. Jan Szosfak ATTORNEY WITNESS MMQQMML Feb. 28, 1967 J, SZOSTAK 3,306,242

BUTTONHOLE MECHANISMS FOR ZIGZAG SEWING MACHINES Filed July 17, 1964 Fig.7

6 Sheets-Sheet 4 9 I92 23 IN V EN TOR.

Jan Szosfak w/ TNESS TORN E Y Feb. 28, 1967 J. SZOSTAK 3,306,242

BUTTONHOLE MECHANISMS FOR ZIGZAG SEWING MACHINES Filed July 17, 1964 6 Sheets-Sheet 5 INVENTOR.

Jan Sz0sfak w/ TNESS RNEY Feb. 28, 1967 J. SZOSTAK 3,306,242

BUTTONHOLE MECHANISMS FOR ZIGZAG SEWING MACHINES Filed Jui 17, 1964 6 Sheets-Sheet 6 I N VE NTOR Jan Sz0sfak WITNESS BY WMQW 91 W 5,5114% RNE Y United States Patent Ofitice 3,395,242 Patented Feb. 28, 1967 3,306,242 BUTTONHOLE MECHANISMS FOR ZIGZAG SEWING MACHINES Jan Szostak, Linden, N.J., assignor to The Singer Company, New York, N.Y., a corporation of New 'Jersey Filed July 17, 1964, Ser. No. 383,411 8 Claims. (Cl. 112158) This invention relates to sewing machines capable of sewing zigzag stitches and, more particularly, to a novel device arranged to control the operation of a household Zigzag sewing machine for the automatic stitching of buttonholes.

Heretofore, it has been known in the sewing machine art to produce buttonholes using a household zigag sewing machine by manually effecting adjustment of the machine controls at the various points of transition about the buttonhole. Such successive manual adjustments are not only tedious, but render the successive production of identically appearing buttonholes practically impossible.

There are also rotating cam devices known in the art which provide for programmed influence of the zigzag sewing machine stitch and work feed controls for the production of buttonholes. Since with these known rotating cam devices, the increment of cam rotation during each stitch regulates the length of the buttonhole, control definition becomes increasingly poorer as the length of the buttonhole is increased and the usefulness of these known rotating cam devices is therefore seriously limited.

This invention provides a control device for the stitching instrumentalities and the work feeding device of a sewing machine for the production of buttonholes with a zigzag sewing machine in which a control element is supported and driven by the sewing machine so as to partake of two different classes of motion, i.e., a translatory motion which does not influence a shift of the sewing machine controls, and an angular motion which is harnessed so as to effect modification of the sewing machine controls. With the present invention, the control element is exchangeable in the sewing machine and the length of the resulting buttonhole may be selected not by varying the increment of control element movement during each stitch, but by selection of an appropriately shaped control element. An advantage of the novel arrangement of this invention is that regardless of the length of buttonhole being stitched, the same optimum number of stitches can be placed at the critical buttonhole ends and the stitch spacing along each side of the buttonhole may be maintained uniform and therefore, the device of this invention servesequally satisfactorily for long as well as short buttonholes. Another advantage of this invention is that simply by the selection of control element, shape characteristics otherthan buttonhole length may be obtained, as for instance, either plain or eyelet end buttonholes may be stitched.

An object of this invention, therefore, is to provide a buttonholing unit for a sewing machine in which an exchangeable control element is operatively connected to shift the various regulators of the sewing machine to produce a buttonhole having a size dictated by the size of the control element.

As illustrated in the accompanying drawings, the exchangeable control element of this invention may take the form of a block which might be termed a template and which is formed with an endless toothed rack. While the control element does not serve directly as a template in the control of the buttonhole shape, it is an advantage of this invention that the devices for harnessing the control element motions are so arranged as to influence the stitching of buttonholes which have the length, proportion, and shape characteristics of the particular endless toothed rack which is inserted in the machine. This is advantageous in that the control elements can provide a visual indication of the resulting buttonhole characteristics.

In the stitching of buttonholes by either manual or automatic control of the stitch and work feed regulating devices of a household zigzag sewing machine, it has heretofore been diflicult to attain a like stitch spacing in the stitches along opposite sides of the buttonhole. Necessary tolerances in the work feed mechanism can result in different feeding action in forward as compared with reverse direction of feed; the feed dog work engaging points are commonly made asymmetrical to favor the more prevalent forward direction of feed used in regular sewing; and the feeding action in one direction or the other may vary disproportionately for different fabrics. This invention provides a novel means, compatible with the buttonhole programming control device, for balancing the effectiveness of the sewing machine work feeding mechanism in the forward and reverse directions of feed so that stitch spacing along opposite sides of the buttonhole may be maintained with a high degree of uniformity.

With the above and additional objects and advantages in view, as will hereinafter appear, this invention comprises the devices, arrangements, .and combinations of parts hereinafter described and illustrated in the accompanying drawings of a preferred embodiment in which:

FIG. 1 represents a front elevational view of a sewing machine having the buttonholing device of this invention applied thereto,

FIG. 2 represents a top plan view of the bracket arm of the sewing machine of FIG. 1 with the top cover plate removed,

FIG. 3 is an enlarged vertical cross sectional View taken substantially along line 3-3 of FIG. 2,

FIG. 4 is a vertical cross sectional view taken substantially along line 4-4 of FIG. 2,

FIG. 5 is a perspective view of a buttonhole template,

FIG. 6 is an enlarged vertical cross sectional view taken substantially along line 66 of FIG. 2,

FIG. 7 represents an enlarged top plan view of a portion of the mechanism carried in the sewing machine arm with the buttonhole template and the hinged template retaining cover removed and with portions of the template guide lever broken away,

FIG. 8 is a horizontal cross sectional view of a portion of the mechanism carried in the sewing machine arm taken substantially along line 8-8 of FIG. 6,

FIG. 9 is a cross sectional view taken substantially along line 9-9 of FIG. 7,

FIG. 10 is a cross sectional view taken substantially along line 10-10 of FIG. 8,

FIG. 11 is a vertical cross sectional view taken substantially along line 1111 of FIGS. 1 and 6, illustrating the work feeding mechanism regulator,

FIG. 12 is a cross sectional view taken substantially along line 12-12 of FIG. 11,

FIGS. 13 to 16 are diagrammatic top plan views of the control mechanism of this invention illustrating the operational sequence of the device and FIGS. 13a to 1621 are representations of the various stages of buttonhole formation corresponding respectively to the control mechanism positional sequence illustrated in FIGS. 13 to 16.

Referring particularly to FIGS. 1, 2 and 6, the conventional elements will be briefly described of a zigzag sewing machine of a type to which this invention is adapted for use.

The sewing machine casing includes a bed 21, a standard 22 rising from the bed, a bracket arm 23 cantilevered from the standard and overhanging the bed and terminating in a sewing head 24. A main drive shaft 25 journaled in the bracket arm carries a handwheel 26 and may be driven as by a worm 27 and a worm wheel 28 from an electric motor (not shown). A crank 29 on the main drive shaft in the sewing head 24 serves to actuate a needle thread take-up lever and also serves to impart endwise reciprocatory movement to a needle bar 31 carrying a sewing needle 32. In addition to endwise reciprocatory movement, the needle bar 31 is journaled in a gate 33 fulcrumed at 34 in the sewing head so as to be shiftable laterally for the sewing of zigzag stitches.

As illustrated in FIG. 6, a miter gear fast on the main drive shaft meshes with a gear 41 carried on a shaft 42 in the standard. The shaft 42 is drivingly connected to the sewing machine loop taker (not shown) disposed beneath the bed 21 to drive the loop taker in timed relation with the endwise reciprocation of the needle in the formation of stitches. Adjacent to the miter gear 41 fast on the main drive shaft is a feed lift eccentric 43 embraced by a feed lift pitman 44 which extends downwardly through the standard. A feed advance cam 45 is fast on the mainshaft adjacent the feed lift eccentric and is embraced by the forked head 46 of a feed advance pitman 47 in the standard. Pivoted to the feed advance pitman is a slide block 48 which is constrained within a guide groove 49 cut in a block 50 which is pivotally supported on a pin 51 fixed in the machine frame. The angular position of the block 50 and particularly of the guide groove 49 therein with respect to the feed advance pitman will influence the amount and direction of work feeding motion, this type of feed regulation being well known in the art.

As illustrated in the drawings the mechanism for influencing the angular position of the block 50 includes a gear segment 52 formed as an integral part of the block 50. Meshing with the gear segment 52 is a worm 53 fast on a hollow shaft 54 journaled in a web 55 formed within the standard and in a bearing 56 carried in the front wall of the standard. The hollow shaft 54 is formed with a flange 57 seated in a counterbore 58 in the bearing 56 and constrained therein by a keeper 59 secured by a screw 60 to the standard to limit axial movement of the hollow shaft 54. A dial 61 secured to the hollow shaft exteriorly of the standard serves for manual adjustment of the angular position of the block 50 and a spring loaded detent ball 62 between a notched track 63 in the dial and the standard may be used to sustain the dial in any selected one of a multiplicity of regular increments of angular adjustment.

Referring to FIG. 1, work feeding is accomplished by a feed dog which works upwardly through slots in a throat plate 71 carried on the bed beneath the needle.

The feed dog is secured on a feed bar 72 which is pivoted to a rock arm 73 fast on a feed advance rock shaft 74 journaled beneath the bed. A rock arm 75 on the feed advance rock shaft is pivoted to the feed advance pitman 47. The feed lift pitman 44 is pivoted to a rock arm 76 fast on a feed lift rock shaft 77 journaled beneath the bed. A rock arm 78 on the feed lift rock shaft is pivotally connected by means of a depending link 79 to the feed bar 72.

The conventional mechanism for imparting and controlling the lateral jogging motion of the needle to produce zigzag stitches will now be described. Driven from a worm 80 on the main drive shaft is a worm wheel 81 fast on a vertical cam shaft 82 journaled on the bracket arm. A constant breadthcam 83 fast on the cam shaft which is thus turned at one half the speed of the main drive shaft is embraced by the forked head 84 of a follower lever 85 which is pivoted by a rivet 86 to a guide block 87. As illustrated in FIGS. 2 and 3, the top of the guide block 87 is formed with a guide slot 88 which accommodates a roller follower 89 journaled on a pin 90 carried by one end of a needle jogging link 91 which link is pivoted at the other end on a pin 92 fixed in the needle bar gate 33.

As illustrated in FIG. 3, the guide block 87 is pivoted by a shouldered screw 93 to an adjustng plate 94 fulcrumed on the machine frame by a shouldered screw 95.

As illustrated in FIG. 7, the needle jogging link 91 between its ends is formed with an elongate slot 96 which embraces a slide block 97 pivoted on a bight adjusting bell crank lever 98 fulcrumed at 99 to the machine frame and having a handle 100 protruding outwardly through the bracket arm. By moving the handle 100, the position of the roller follower 89 may be selected along the guide slot 83 to influence the magnitude of lateral jogging motion imparted to the needle. When the roller follower 89 is positioned along the guide slot 88 with its axis coinciding with that of the shouldered screw 93 no jogging motion will be imparted to the needle and the magnitude of lateral jogging motion will increase as the roller follower is shifted along the guide slot away from the shouldered screw 93.

The field or neutral position of the needle jogging may be regulated left, right or center by swinging the plate 94 about its fulcrum screw 95. For effecting neutral position adjustment a bracket 101 secured to the plate 94 carries a plunger 102 which protrudes through a slot 103 in the bracket arm and has a handle 104 affixed to its free extremity. The bracket arm slot 103 is formed with three notches 105, 106 and 107 corresponding respectively to the left, center and right neutral positions of adjustment any one of which notches may be entered by a conical enlargement 108 on the plunger when the plunger is drawn outwardly. A spring clip 109' secured to the plunger 102 includes a tang 110 which engages the bracket 101 when the plunger is drawn outwardly so as to releasably constrain the plunger with the conical enlargement 108 in engagement with a selected one of the notches 105, 106 or 107. When the plunger is shifted inwardly into the position illustrated in FIG. 3, the adjusting plate 94 is free to be turned to effect a change in the neutral position adjustment.

The above described sewing machine is thus a conventional plain zigzag sewing machine in which the width or bight of zigzagging may be manually adjusted using the handle 100, the neutral position needle jogging may be manually set at either left center or right using the handle 104 and the direction and extent of work feed may be regulated manually by turning the dial 61.

In order to adapt the conventional manually controlled zigzag sewing machine for automatic production of buttonholes in accordance with this invention, a control device indicated generally as is carried in the bracket arm of the sewing machine and is illustrated particularly in FIGS. 2 to 4 and 6 to 10. The control device 120 provides for utilization of the motion of the main drive shaft to provide a novel programmed control of the zigzag stitch and work feed controls to produce buttonholes. In accordance with this invention a horizontal support plate 121 is secured above the main drive shaft 25 within the bracket arm as by fastening screws 122. The upper surface of the horizontal support plate 121 is formed with a pair of shallow recesses 123 and 124 illustrated clearly in FIG. 8. Protruding from beneath the recess 123 the support plate is formed with a lateral extension 125 and adjacent to the recess 124 the support plate is formed with a lateral extension 126. An additional spacing block 127 may be inserted between the support plate 121 and a bearing web 128 in the bracket arm to provide increased stability for the support plate 121. Journaled through the support plate 121 in the area of the recess 123 is a shaft 129 shown in FIG. 4 having a pinion 130 fixed thereto above the support plate and with the upper extremity 131 of the shaft 129 protruding above the pinion. A ratchet wheel 132 is fixed to the shaft 129 below the support plate 121. As illustrated in FIGS. 6 and 8, an operating lever 133 is fulcrumed on the depending extremity of the shaft 129 and extends beneath the lateral extension 125 of the support plate. The operating lever 133 carries a pivoted pawl 134 which is biased into en-- gagement with the ratchet wheel 132 by a spring 135 carried on a screw 136 threaded through the operating lever and a coil spring 137 extending between the screw 136 and a pin 138 carried in the lateral extension 126 of the support plate urges the operating lever 133 in a counterclockwise direction as viewed in FIG. 8.

A roller follower 139 carried beneath the operating lever 133 bears against a face cam 148' fast on the main drive shaft so that as the main shaft turns, the action of the face cam 140 and the coil spring 137 will serve to vibrate the operating lever 133 to impart by way of the pawl 13-4 step-by-step increments of turning movement to the ratchet wheel and pinion 130. A retrograde pawl 141 pivoted beneath the support plate and biased by a spring 142 against the ratchet wheel will insure motion of the pinion 130 only in a clockwise direction as viewed in FIGS. 2, 7 and 8.

A throw-out lever 143' is fulcrumed on the shaft 129 beneath the pinion 130 and within the recess 123. An arched spring arm 144 formed on the throwout lever extends through a slot 145 in the bracket arm and is provided with an upturned tang 146 within the bracket arm slot 145. The throw-out lever is formed with a lateral arm 147 upturned to abut a pin 148 extending upwardly from the operating lever 133. By means of a finger grip 149 on the spring arm 144 outside the bracket arm, the throw-out lever may be turned clockwise as viewed in FIG. 7 so that the lateral arm 147 will engage the pin 148 to carry the roller follower139 beyond the influence of the face cam 140. The spring arm 144 will urge the tang 146 into a locking notch 150 in the bracket arm slot 145 to hold the lever 143 in the clockwise throw-out position, and a second locking notch 151 is provided into which the tank 146 will be urged to constrain the throwout lever in an inoperative position. l

Pivoted as at 152 atop the support plate 121 is a swinging guide member 153 formed with upstanding side flanges 154 which are undercut as at 155 as shown clearly in FIGS. 4 and 9. The guide member 153 is formed with a laterally elongate clearance hole 156 through which the pinion 130 extends so that the guide member may partake of limited swinging movement free of the pinion.

Slidably arranged in the guide member is a template carrier 157 formed with tangs 158 embraced within the undercut ways 155 of the guide member flanges 154. The template carrier is formed with a central opening 159 adapted snugly to accommodate an exchangeable template 160 of the type illustrated in FIG. 5. A closure 161 hinged on the template carrier is formed with a spring finger 162 and with a finger grip 163 to constrain a selected template within the central opening of the template carrier.

Referring to FIG. 5, the exchangeable template 160 is formed with a body portion 164 which is accommodated snugly but freely within the opening 159 in the template carrier and suspended therein by a lateral flange 165 on the template which rests upon the template carrier 157. The underface of the template body portion is formed with an endless series of rack teeth 166 in an oblong arrangement i.e., with straight ra-ck portions 167 and with rounded end portions 168. An oblong groove 169 is also formed in the under face of the template body within the series of rack teeth 166.

'For exchange of templates, a hinged cover 170 is provided at the top of the bracket arm exposing, when opened, the hinged closure 161 on the template carrier. When the hinged closure is turned upwardly, a template having the desired proportion of straight androunded end portions 167 and 168 of rack teeth may beinserted into the opening 159 of the template carrier. When inserted, the rack teeth 166 of the selected template will mesh with the pinion 130 and the pinion shaft extremity 131 will seat within the oblong groove 169 of the template. The closure 16 1 when turned down into the position illustrated in FIG. 6'will'constrain the template in place by engagement 6 of the spring finger 162 on the edge of the template carrier 157.

With a template in place and the face cam 140 on the sewing machine main drive shaft operative to impart step-by-step turning movement to the pinion 130, the pinion when in mesh with a rounded end potrion 168 of the rack will shift the template carrier 157 and the guide member 153 laterally of the sewing machine bracket arm and cause the guide member to partake of a gradual turning movement about the axis of the pivot 152 for the guide member. This angular motion of the guide member is harnessed as will be described herebelow to effect a gradual change of the ordinarily'manual stitch and work feed regulators from settings appropriate for the sewing of one side of a buttonhole to settings appropriate for the sewing of the other side, and during this gradual transition an end of the buttonhole will be produced. While the pinion meshes with a straight rack portion 167, the template carrier will slide along the ways 155 of the guide member imparting no motion to the guide member and the sewing machine controls will be maintained for a period of sewing machine actuation which is proportional to the length of the straight rack portions and thus the length of the buttonhole may be influenced by the selection of a template having a requisite length straight rack portion 167.

The mechanism for harnessing the angular motion of the guide member 153 for influencing the stitch and work feed regulating devices of the sewing machine comprises a link 180, FIGS. 6, 8 and 9 are arranged in the recess 124 of the support plate 121 and pivoted at 181 to the guide member 153 at a point spaced from the fulcrum pivot 152 for the guide member. The link is pivoted at 182 to one arm of a bell crank 183 fulcr-umed on the pin 138 carried in the support plate extension 126. The other arm of the bell crank 183 carries a pivot pin 184 secured by a spring keeper 185 which pin is embraced by a link 186 for controlling the work feed regulating means and by a link 187 for controlling the neutral position of needle zig-zag-ging motion.

The link 187 influences neutral position of needle zigzag motion by way of a pin 188 fixed transversely through the link 187, the upper extremity of which pin enters an arcuate slot 189 formed beneath the neutral position adjusting plate 94. The lower extremity of the pin 188 is embraced by the bifurcated arm 190 of a bell crank fulcrumed on a pin 191 FIG. 6 carried in a bracket arm 192 fixed by screws 193 to the lateral extension 125 of the support plate 121. The other arm 194 of the bell crank is a spring arm which extends through a slot 195 formed in the sewing machine bracket arm and is fitted exterioriy of the machine frame with a handle 196. A tang 197 formed on the spring arm 194 can cooperate with any one of a series of locking notches 198 formed in the slot 195 to position the pin 188 in diflerent positions along the arcuate slot 189; by this means the angular motion of the guide member 153 can be made to have more or less of an influence upon the setting of the neutral position control plate 94. A locking notch 199 formed in the slot 195 serves to lock the bell crank 190, 194 with the pin 188 positioned out of the arcuate slot 189 and into an adjoining widened portion 200 in which position the angular motion of the guide member 153 can have no influence upon the setting of the neutral position control plate 94.

The link 186 for influencing the setting of the work feeding device is pivotally connected by the shouldered screw 210 to a rock arm 211 fixed to a rock shaft 212 journaled in a bracket 213 secured by screws 214 within the sewing machine bracket arm. As illustrated in FIGS. 6, l1 and 12 a bifurcated rock arm 215 fast on the rock shaft 212 embraces a threaded clamp fastener 216 which may be secured in selected position along the bifurcated rock arm 215 and provides a pivotal connection between the rock arm 215 and a link 217 which depends within 7 the standard 22 and is pivoted at 218 to a rock arm 219 secured by a setscrew 220 to a rod 221 journaled within the hollow feed regulating shaft 54.

The rod 221 is in the usual condition freely journaled within the hollow shaft 54 and extends outwardly beyond the feed adjusting dial 61 on the hollow shaft 54. The rod 221 is formed with a transverse slot 222 elongate lengthwise of the rod to accommodate a pin 223 slidably but non-rotatably securing to the rod 221 a dial 224. The rod 221 is also formed with a transverse slot 225 elongate lengthwise of the rod to accommodate a fulcrum pin 226 fixed in bifurcated arms 227 of a locking lever 228. The fulcrum pin 226 is fixed asymmetrically in the bifurcated arms 227 so that when the locking lever is turned to the right as viewed in FIG. 1, the arms 227 will urge the dial 224 toward the rock arm 219 and will thus clamp the rod 221 to the hollow shaft 54 so that the two will turn as a unit. A stop screw 229 threaded into the free extremity of the rod 221 and abutting the fulcrum pin 226 in the clamped position of the parts may be used to attain a micrometer control of the clamping effect attained by the locking lever 228. When the locking lever is turned to the left as viewed in FIG. 1, the rod 221 will be freed to turn relatively to the hollow shaft 54 and a Spring 230m an axial bore 231 in the rod and abutting the fulcrum pin 226 will serve to deter accidental turning movement of the locking lever.

In the automatic production of buttonholes it is necessary that the angular motion of the guide member 153 at the ends of the buttonhole change the setting of the work feed regulating device from one direction of work feed to the opposite direction. To insure that the locking lever 228 may be turned to effect locking of the rod 221 relatively to the hollow shaft 54 in a position of the parts which will effect a feed reversal in response to the angular guide member motion, a radial slot 240 is formed in the feed regulating dial 61 opposite a plunger 241 slidable in the dial 224 on the rod 221. A retracting spring 242 on the plunger urges the plunger in a direction away from the feed regulating dial 61 and an eccentric 243 is formed on the extremity of the plunger which is continguous to the dial 61 and of a diameter slightly smaller than the width of the radial slot 240. The plunger 241 is arranged in that angular position on the dial 224 relatively to the radial slot 240 that when the eccentric 243 is brought opposite the radial slot 240 midway about the end of a buttonhole being formed under the control of the guide member 153, the stitch length of the work feeding mechanism will be substantially reduced to zero. When the plunger 241 is depressed seating the eccentric in the radial slot 240 and the locking lever 228 is turned to free the rod 221 in the hollow shaft 54, the plunger may be turned to effect a micrometer adjustment of the angular position of the rod 221 relatively to the hollow shaft to favor to a selected degree either the forward or the reverse direction of feed. When the feed is properly balanced using this micrometer adjustment so as to be equally effective in the forward and reverse directions when influenced by the control device 120 to suit the specific conditions encountered, the locking lever 228 may be turned to the right as viewed in FIG. 1 to lock the parts in the adjusted position.

Operation To ready the sewing machine for automatic production of buttonholes using the control device of this invention, a selected template 160 is first positioned in the template carrier 157. Referring to FIG. 1, the width or bight adjusting handle 100 is set to a position corresponding to slightly less than half the maximum permissible width of zigzag stitch; the feed regulating dial 61 is turned until the radial slot 240 is aligned with the eccentric 243 and the plunger 241 may be depressed and turned to effect the desired micrometer adjustment and then the locking lever 228 is turned to the right into the position illustrated in FIG. 1. The neutral position handle 104 is depressed until the spring tang locks the conical portion 108 of the plunger 102 out of the range of the notches 105, 106 and 107 and frees the neutral position influencing plate 94 for automatic control.

The handle 196 is shifted to move the tank 197 out of the locking notch 199 into one of the notches 198 thus carrying the pin 188 into the arcuate slot 189 and rendering the connection from the control device to the neutral position regulating plate 94 effective. The greater the distance that the handle 196 is shifted from the locking notch 199 the smaller will be the total width of the buttonhole and of the cutting space between the stitches at each side of the buttonhole.

The handle 149 is shifted to the right as viewed in FIG. 1 and the tang 146 seated in the notch 151 to lock the handle 149 in a position in which the ratcheting device for the pinion will be operative thus completely readying the sewing machine for the automatic sewing of buttonholes.

FIGS. 13 to 16 are diagramatic top plan views of the pinion 130, template 160, template carrier 157 and guide member 153 and including fragments of the linkage 180, 183, 186 and 187 connecting tht guide member 153 with the work feed and neutral position regulating mechanisms of the sewing machine. These figures illustrate the sequence of operation in the formation of a buttonhole and for this purpose each is accompanied by a representation, FIGS. 13a tol6a, in fine lines of the buttonhole stitching ultimately to be performed with those portions of the buttonhole illustrated in heavy lines which have been thus far stitched in the sequence of operation and including an arrow indicating the position of the sewing machine needle.

Stitchin of the buttonhole may be initiated as illustrated in FIG. 13 with the pinion 130 about to mesh with the curved rack portion 168 at one end of the template. With the pinion turning in step-by-step fashion in the direction illustrated by the curved arrow in FIG. 13 meshing of the pinion with the curved rack portion 168 will cause the guide member 153 to be shifted angularly about the pivot 152 from the position illustrated in FIG. 13 to that illustrated in FIG. 14 with a consequent gradual shift of both links 186 and 187 to reverse the direction of feed and transpose the neutral position of needle vibration. The result in the buttonhole stitching as illustrated in FIG. 14a is the production of one end of the buttonhole.

Continued operation of the sewing machine gives rise to tracking of the pinion 130 along one of the straight rack portions 167 of the template 160 during which, the guide member 153 remains in the position illustrated in FIGS. 14 and 15, since the template carrier 157 partakes only of translatory motion along the ways of the guide member 153. The links 186 and 187 will remain motionless during the period and as illustrated in FIG. 15a one side of the buttonhole will be stitched. It will be appreciated, therefore, that the length of the straight rack portion 167 of the template 160 serves as a timing device to dictate the length of the resulting buttonhole. It is pointed outthat the kinematics of the linkage 211-219 for controlling the work feed regulating mechanism may be arranged to provide for stitching of buttonholes closely approximating the length of the rack portions 167 of the template and that the clamp fastener 216 provides for a fine adjustment of buttonhole length whereby a visual correlation may be established for the operators benefit between the size of the template rack and the size of the buttonhole to be produced.

Comparison of FIGS. 15 and 16 will illustrate diagrammatically the result of combined sewing machine operation during which the pinion 130 tracks the opposite curved rack portion 168 to complete the opposite end of the buttonhole as illustrated in FIG. 16a. Continued sewing machine operation then serves to complete the sewing of the other side of the buttonhole to conclude the buttonhole sewing sequence.

The total Width of the buttonhole produced by the device of this invention as well as the cutting space between rows of stitches at each side of the buttonhole may be regulated by either or both of two adjustments, i.e.,

either by the setting of the bight of zigzag stitching using handle 100 or by using handle 196 and selecting one of the locking notches 198 to influence the degree of control which the template 160 will exert upon the neutral position variation during buttonhole sewing.

While the clamp fastener 216 in providing a fine adjustment of buttonhole stitch spacing may be use-d to influence accurate correlation of the buttonhole length with that of the rack in the template, the clamp fastener 216 may also be used to provide for a regulation of the buttonhole length larger or smaller than the template rack should buttonholes be desired of length slightly different from that of the available template rack.

Having thus described the nature of the invention, what I claim herein is:

1. A buttonholing device in a sewing machine having a frame, an endwise reciprocating and laterally jogging needle and a work feeding device carried in said frame, actuating mechanism in said frame for operating said needle and said work feeding device, a first shiftable regulator in said frame operatively connected to said needle actuating mechanism for controlling the lateral position of needle jogging, and a second shiftable regulator in said frame operatively connected to said work feeding actuating mechanism for controlling the direction and magnitude of said work feeding device, said buttonholing device comprising an exchangeable template carried in said sewing machine frame, and means operatively connecting said template with said first and second shiftable regulators to produce automatically a buttonhole having a size dictated by the size of the template.

2. A buttonholing device in a sewing machine having a frame, an endwise reciprocating and laterally jogging needle and a Work feeding device carried in said frame, actuating mechanism in said frame for operating said needle and said work feeding device, a first shiftable regulator in said frame operatively connected to said needle actuating mechanism for controlling the lateral position of needle jogging, and a second shiftable regulator in said frame operatively connected to said work feeding actuating mechanism for controlling the direction and magnitude of said work feeding device, said buttonholing device comprising an exchangeable template shiftably supported in said sewing machine frame, drive means operated by said sewing machine actuating mechanism for imparting step-by-step movement to said template in a closed path, and linkage in said frame connectable to said first and second shiftable regulators and responsive to movement of said template to shift said regulators for the automatic production of a stitched buttonhole.

3. A buttonholing device in a sewing machine having a frame, an endwise reciprocating and laterally jogging needle and a Work feeding device carried in said frame, actuating mechanism in said frame for operating said needle and said work feeding device, a first shiftable regulator in said frame operatively connected to said needle actuating mechanism for controlling the lateral position of needle jogging, and a second shiftable regulator in said frame operatively connected to said work feeding actuating mechanism for controlling the direction and magnitude of said work feeding device, said buttonholing device comprising a lever, means defining a fulcrum for said lever in said sewing machine frame, a track formed on said lever radially of said fulcrum, linkage in said frame responsive to angular movement of said lever about said fulcrum, means for at will connecting said linkage to said first and said sec-ond shiftable regulators, a pinion journaled in said sewing machine frame, drive means operated by said actuating mechanism for imparting step-by-step rotary motion in one direction to said pinion, a template formed with an endless rack, and means supporting said template for translatory sliding movement along said track in said lever and with said template rack in mesh with said pinion.

4. A buttonholing device as set forth in claim 3 in which said drive means for said pinion includes a manually operable throw-out element in said frame effective at will to render said drive means for said pinion ineffective.

5. A buttonholing device as set forth in claim 3 in which said means connecting said linkage to said first shiftable regulator includes an element adjustable exteriorly of said frame for varying the motion imparted to said first shiftable regulator by said linkage.

6. A buttonholing device as set forth in claim 3 in which said means connecting said linkage to said second shiftable regulator includes a clamping device adjustable exteriorly of said frame for effecting said connection of said linkage with said second shiftable regulator in any initial position of adjustment of said second shiftable regulator.

7. A buttonholing device as set forth in claim 6 in which said second shiftable regulator includes a hollow rotatable adjusting shaft for said work feeding device and in which said clamping device includes a rod connected to said linkage and journaled Within said hollow feed adjusting shaft and means for at will rotationally interlocking said rod and said feed adjusting shaft, and manually operable means interposable between said rod and said feed adjusting shaft in a limited range of positions of said feed adjusting shaft which range includes a posi tion corresponding to zero stitch length for providing a fine adjustment of the angular relation of said rod relatively to said feed adjusting shaft.

8. A buttonholing device as set forth in claim 3 in which said endless rack in said template is formed with straight rack portions disposed substantially parallel to said track when said template is sustained in said supporting means, and in which said means connecting said linkage to said second shiftable regulator is adjustable to provide for that stitch length while said pinion is in mesh with said straight rack portions as will produce a stitched buttonhole having a length substantially equal to the length of said straight rack portions in said template.

No references cited.

JORDAN FRANKLIN, Primary Examiner. RICHARD J. SCANLAN, 111., Examiner. 

1. A BUTTONHOLING DEVICE IN A SEWING MACHINE HAVING A FRAME, AN ENDWISE RECIPROCATING AND LATERALLY JOGGING NEEDLE AND A WORK FEEDING DEVICE CARRIED IN SAID FRAME, ACTUATING MECHANISM IN SAID FRAME FOR OPERATING SAID NEEDLE AND SAID WORK FEEDING DEVICE, A FIRST SHIFTABLE REGULATOR IN SAID FRAME OPERATIVELY CONNECTED TO SAID NEEDLE ACTUATING MECHANISM FOR CONTROLLING THE LATERAL POSITION OF NEEDLE JOGGING, AND A SECOND SHIFTABLE REGULATOR IN SAID FRAME OPERATIVELY CONNECTED TO SAID WORK 